diff --git a/setup.py b/setup.py
index 263753a2..cd207a50 100755
--- a/setup.py
+++ b/setup.py
@@ -304,6 +304,7 @@ def gssapi_modules(lst):
     long_description=long_desc,
     license='LICENSE.txt',
     url="https://github.com/pythongssapi/python-gssapi",
+    python_requires=">=3.6.*",
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Programming Language :: Python',